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Role of perisynaptic parameters in neurotransmitter homeostasis—Computational study of a general synapse
Author(s) -
Pendyam Sandeep,
Mohan Ashwin,
Kalivas Peter W.,
Nair Satish S.
Publication year - 2012
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.21547
Subject(s) - neurotransmitter , synapse , neurotransmitter agents , neurotransmitter transporter , homeostasis , neuroscience , synaptic cleft , neurotransmission , extracellular , neurotransmitter receptor , biology , autoreceptor , chemistry , microbiology and biotechnology , biochemistry , central nervous system , receptor , serotonin
Extracellular neurotransmitter concentrations vary over a wide range depending on the type of neurotransmitter and location in the brain. Neurotransmitter homeostasis near a synapse is achieved by a balance of several mechanisms including vesicular release from the presynapse, diffusion, uptake by transporters, nonsynaptic production, and regulation of release by autoreceptors. These mechanisms are also affected by the glia surrounding the synapse. However, the role of these mechanisms in achieving neurotransmitter homeostasis is not well understood. A biophysical modeling framework was proposed, based on a cortico‐accumbens synapse example case, to reverse engineer glial configurations and parameters related to homeostasis for synapses that support a range of neurotransmitter gradients. Model experiments reveal that synapses with extracellular neurotransmitter concentrations in the micromolar range require nonsynaptic neurotransmitter sources and tight synaptic isolation by extracellular glial formations. The model was used to identify the role of perisynaptic parameters on neurotransmitter homeostasis and to propose glial configurations that could support different levels of extracellular neurotransmitter concentrations. Ranking the parameters based on their effect on neurotransmitter homeostasis, nonsynaptic sources were found to be the most important followed by transporter concentration and diffusion coefficient. Synapse, 2012. © 2012 Wiley Periodicals, Inc.